The Ledger·July 2026

The $667 Rule

The margin that decides retirement isn't the balance. It's $667 a month.

Case 001 asks a plain question: a fictional couple, both 62, with $840,000 of investable assets and no pension, wants to stop working now. Can they? The verdict we published is a conditional yes — and the condition that matters most is not the portfolio. It is $667 a month.

Here is the experiment, with its parameters in the open.

ASSUMPTION The case inputs are explicit and adjustable: $840,000 invested, a $60,000-a-year lifestyle budget in constant 2026 purchasing power, healthcare and federal tax modeled separately, and a small low-rate mortgage whose payment ends at 70.

FACT For anyone born in 1960 or later, Social Security's full retirement age is 67. In the scenario below, both spouses claim at 67.

ASSUMPTION The market path is deliberately bad: real returns of −20%, −8%, +2%, +5%, +7%, then 3% a year. It is a designed stress sequence — not a forecast, not a history, not a probability.

Hold all of that constant and move one dial — lifestyle spending, in $2,000 steps.

Read the bottom row against the $60,000 row. Between $60,000 and $68,000 a year sits $8,000 — about $667 a month. That single difference moves the modeled outcome by roughly fourteen years of portfolio longevity: from ending at 95 with $165,560 still invested to running out around 81.

Why spending beats the balance

"Can we retire?" is usually asked as a question about the balance. The most important finding in this case is that the balance cannot answer it alone. The same $840,000, on the same bad market path, produces every outcome from $407,878 remaining to depletion at 81. The balance doesn't decide which of those futures the couple gets — the spending row does. Under these assumptions, a $2,000 increase in lifestyle spending materially compresses the margin, and a $4,000 increase triggers depletion at age 90.

Spending is also the one large variable a household actually steers. Returns arrive and rules change, but the travel budget, the second car, and the grocery bill are decisions. That is what makes this table useful rather than frightening: every row is a plan someone could choose, and the distance between rows is measured in months of runway, not in luck.

The flexibility dividend

MODEL OUTPUT We also tested one pre-committed rule: after any calendar year with a real return below −5%, spend $6,000 less the following year. On the stress path, that single agreement raises the age-95 ending balance from $165,560 to $200,905. The exact rule matters less than the fact that it existed before the bad year arrived. Pre-committed flexibility has measurable value.

What to do with this

Three questions to investigate — not advice:

1. What did our lifestyle actually cost over the last twelve months — from bank and card statements, not from memory — and which row of this table is that?
2. If markets fell 20% next year, which specific $500 a month would we pause — and have we agreed on it in writing before it happens?
3. What single change — housing, one car, one subscription bundle, one trip — would move us one row up this table, and what would it honestly cost us in life?

The free Retirement Stress Test reproduces this table live for your own numbers — the same model we used on the case, never a lite version. The spending research, including what we haven't answered yet, lives at Decision 03: What can we actually spend? Case 001's complete file — every source, every claim graded — is on the record at Case 001.

---

Mark and Diane are fictional composites. Model outputs are deterministic illustrations under stated assumptions — not forecasts or guarantees. Nothing here is individualized financial, tax, or insurance advice.